[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] qcow2: Unset zero_beyond_eof in save_vmstate
|
From: |
Eric Blake |
|
Subject: |
Re: [Qemu-devel] [PATCH] qcow2: Unset zero_beyond_eof in save_vmstate |
|
Date: |
Mon, 21 Oct 2013 21:37:05 +0100 |
|
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 |
On 10/20/2013 08:52 PM, Max Reitz wrote:
> Saving the VM state is done using bdrv_pwrite. This function may perform
> a read-modify-write, which in this case results in data being read from
> beyond the end of the virtual disk. Since we are actually trying to
> access an area which is not a part of the virtual disk, zero_beyond_eof
> has to be set to false before performing the partial write, otherwise
> the VM state may become corrupted.
>
> Signed-off-by: Max Reitz <address@hidden>
> ---
> Follow-up to (depends on):
> - qcow2: Restore total_sectors value in save_vmstate
Reviewed-by: Eric Blake <address@hidden>
Do you have test cases that demonstrate the corruption pre-patch?
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature